action fails if packer already exists on the machine

If the setup-packer action is run and the agent already has packer installed, the step fails without providing any useful context.

# Expected Behavior

I would expect the step to detect that the end result of the action has been acheived (i.e. the requested packer version is present on the agent) and the step succeeds

## Current Behavior

```
Run hashicorp/setup-packer@v3
Installing packer:1.11.1 and adding it to GitHub Actions Path

## Steps to Reproduce

1. Create a github action that targets a runner with Packer installed
1. Call the setup-packer@v2 action
1. Execute your action

## Environment